How Hand Sanitizer Works (And Why It Isn't a Substitute for Soap)

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You likely know it's mostly alcohol. So why doesn't hand sanitizer look, smell, and feel like the stuff doctors use to clean their tools? (Or for that matter, the kind we drink?) The difference is in the details, as the American Chemical Society's Reactions video explains below.

Technically, most popular hand sanitizers are made from forms of alcohol including ethanol (the same stuff in wine, beer, and liquor) and isopropanol, which is found in rubbing alcohol. These dissolve the outer coating of viruses and bacteria, which ultimately ends up killing the pesky skin hitchhikers.

That said, the substances above only comprise around 70 percent of the active ingredients in hand sanitizer. The rest are added to give the drugstore staple its gel-like consistency, softening properties, and its botanical fragrance. In some cases, manufacturers might even add some foul-tasting compounds to the mix, to deter users from potentially taking an ill-advised sip.

These mixtures are typically billed as "killing 99.99 percent of germs." In lab conditions, they can nearly eradicate certain strains of bacteria, but not all of those commonly found on your hands. Nevertheless, they do a pretty effective job.

Some health-conscious purchasers may worry that hand sanitizer will lead to the emergence of super-germs, kind of like antibiotic resistance. Here's the good news: Bacteria can't develop ultra-strong proteins or membranes as a response to being detonated by alcohol, so feel free to keep on squirting the aloe-scented stuff all winter long. The bad news? It doesn't physically wash dirt from hands. For that, you'll have to rely on old-fashioned soap and water (which don't fit nearly as conveniently into pockets or purses).

Find out what other compounds lurk invisibly inside your trusty bottle of hand sanitizer, and how it works to blast germs, by watching the video below.